


Calculus is Easy

by Frostfire



Category: Numb3rs
Genre: M/M, Mathematics
Language: English
Status: Completed
Published: 2005-10-17
Updated: 2005-10-17
Packaged: 2017-12-23 16:41:24
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,878
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/928755
Author URL: https://archiveofourown.org/users/Frostfire/pseuds/Frostfire
Summary: <blockquote class="userstuff">
              <p>Colby learns some calculus.</p>
            </blockquote>





	Calculus is Easy

Don’s been going nonstop for something like ten thousand hours, now, and David and Colby have been shooting Energizer Bunny jokes back and forth since yesterday. The man does not know when to lie down and take a break. Colby’s started to really, really hope that Don’s some sort of crazy FBI exception—what did Charlie call it, an outlier—because _Jesus_ , he does not want to spend the best years of his life working hundred-hour weeks in order to get a promotion.

This isn’t even a really vital case—no murder, no rape, nothing but someone messing around with bank systems, stealing money without anyone realizing it—but no way will that stop SuperAgent Eppes. Don’s said that he saw something similar last year, but that they’d found the guy first and the crime second—he’s been comparing the two casefiles for a couple of days now. David has decided that Don is insane, because they didn’t actually _solve_ the case last year. The guy just fell into their hands, David says, and apparently now Don thinks he should have enough experience with this kind of thing to do this.

Upshot is, they don’t know how to find the guy just from what the bank’s given them, despite Don Eppes’ one-man war.

They’re on Round Seven of finding everyone in the world who works or worked at the bank, and everyone that they’re related to or going out with or passed on the street once last year, and finding out basically nothing. Don’s back at the office, staring at the evidence—all computer printouts—and trying to triage suspects using only the power of his mind. Given a choice, Colby would rather be at the house of Ms. Elizabeth Drear, trying to convince her that this isn’t about the pot she’s growing in her backyard, while subtly insinuating that he’d totally be willing to forget about the pot if she’d give him some information to help the _bank fraud case_ , except she won’t because she doesn’t know anything.

Actually, given a choice, he’d _rather_ be golfing. But whatever. Anything is better than hanging around Don when he thinks he should be solving a case but can’t.

Colby finishes up with Ms. Drear— _finally_ —and meets up with David at the office. “Any luck?”

David shakes his head. “You?”

“Nothing. What do you want to bet Don’s head has exploded since this morning?”

“No bet,” David sighs. “Terry used to be able to calm him down.”

The more Colby hears about Terry, the more he wants to meet her, the mythical female embodiment of calm, competence, and Don-knowledge. Rumor is she used to date him, a million years ago. Have to admire a woman like that, even if he’s never laid eyes on her. “How about we bet on whether he goes home tonight?”

“No way,” says David. “Charlie’s back tonight.”

“Oh, right. Good.” Colby’s pretty sure the only reason the case has taken so long is that Charlie’s been away at some huge math conference—and who knew there were _math conferences_? That’s one of the funniest things he’s learned in a while, that there are big groups of math professors getting together from all over the country and talking to each other about new math problems and advances in the mathematical field and math papers and math articles and maybe having, like, math _parties_ or something. Weird. “Don was saying something about it—he’s coming back and going straight to teach a class, so he’s not going to be free until eight or so—”

“Which is less than an hour away.”

“Oh, God. Tell me you’re lying.” Colby looks at his watch. Looks again. “Damn.”

“Sorry. We better go report to Don. He’s going to have us checking in with Charlie every five minutes until he’s done with this.” David rubs his temples. “I need to spend time with someone not named Eppes.”

“Hey,” says Colby, “come on. I bet you aren’t even a little sick of their dad yet.” He likes Mr. Eppes, himself. A really nice guy, hard to see how he raised two such _totally insane_ sons.

Although, honestly—while Don can really start grating on the nerves, especially when he’s fixated on a case like this, Colby likes Charlie. Sure, he’s a genius, which usually pisses Colby off, but with Charlie it’s just—kind of cool. Charlie’s not an asshole about having more brains in his little finger than Colby has in his skull. He likes explaining stuff, and he’s good at doing it without making you feel stupid. And he likes _Colby_ , which is more than Colby can say for most people in the office. Although he and David are finally starting to become work-buddies, at least.

The dad comment gets a snicker. “It’s the genes,” says David. “I can’t take any more Eppes genes. Come on, let’s go see if we’re allowed to go home tonight.”

But when they find Don, the joking kind of evaporates, because _Jesus_ does SuperAgent need to get some sleep. Colby’s got to wonder if Don’s going through something in his personal life ( _what_ personal life, though?) that’s making him put in the hours on this thing. Or maybe workaholicism comes in waves and Don’s at a peak. Whatever, he looks like he’s about to collapse.

“Oh, great,” Don says as Colby and David come in. “Find anything?” He waves Megan over from the other room.

They shake their heads, and Don sighs and says, “Okay. Bring some of this stuff home and look at it tonight, all right? Maybe you’ll see something I didn’t. I’m going to head over to the school and see if I can get Charlie to do something with this. If it’s just an easy equation, this could be over by tomorrow.”

Colby’s not sure what makes him offer—maybe it’s just that Charlie does like him, and sometimes you want to hang with someone who likes you, for once. Or maybe he wants Don to not die in a car crash tomorrow because he hasn’t slept in a week. Whatever, he hears himself saying, “You know, CalSci is on my way home. I could stop there and just have Charlie call you when he has something.”

Don stares at him like he’s speaking Hindi or something. After a second, Megan jumps in. “Good idea. More work for him, more sleep for us. I know I need some downtime.”

Colby watches, fascinated, as Don’s wiped-out brain tries to form an argument, until he finally shrugs and says, “Okay, go ahead. But _call me_ if there’s any kind of breakthrough, understand?”

“Definitely,” says Colby, and starts the process of leaving the office while Don gets on the university website and looks up the building and room number of the class Charlie’s teaching right now.

David catches him just as he’s leaving. “What was that, you kissing ass now?”

“No way. I just think life’ll be a little better if my boss sleeps tonight, you know? Plus, every time I see Charlie I learn something. Almost makes me feel like I’m smart.”

David grins and shakes his head, and leaves him to it.

 

It’s weird, Colby thinks while he drives, how Charlie’s a full professor. He comes across like a child prodigy, a college kid, hanging around in jeans and button-downs, with Don always giving him the kid-brother treatment. But he’s a _professor_ , stands at the front of lecture halls and teaches classes, probably has grad students older than he is, publishes papers and gives tests. Every so often, Colby tries to reconcile Charlie with his professors in college, and just—can’t. Of course, he only took the basic math requirements, didn’t even get to calculus. Maybe the math department was different.

Or maybe Charlie’s just a freak. Uh-huh.

On campus, he wanders through a maze of red-brick buildings, looking for the right three-letter abbreviation and having flashbacks to undergrad, degree in criminal justice. By the time he finds the building named, for whatever reason, SGM, it’s seven-forty.

Charlie’s classroom door is open, and he stops just outside and watches for a little while. Charlie totally doesn’t notice; he’s too busy writing out crazy symbols on the board, talking as fast as he writes, explaining stuff that Colby will never, ever understand. A couple of the students stare at him, tired guy in a suit who doesn’t belong here. It’s a small class, fifteen or twenty kids, and judging by the squigglies on the board, pretty advanced.

“Okay,” says Charlie. “Everyone understand that? Speak now or lose ten percent on the midterm.”

Nobody asks anything, so Charlie smiles and says, “All right. You’re free to go. The midterm’s on Tuesday, and I’ll be in my office at the usual time tomorrow, so if you have any trouble, come see me.” They start packing up, and three of the girls instantly come up and start talking to him. Colby shakes his head. College undergrads _throwing_ themselves at him. He bets this happens in all of Charlie’s classes. After all, he’s way, way younger and cuter than your average college professor.

Five more minutes go by, until Charlie finally looks up and double-takes. “Colby, hi. Did my brother send you?”

The girls look both annoyed at the interruption and curious as to who the hell Colby is. He gives them a brief _fuck you too_ look and says, “Yeah, kind of. We’ve got this case, and we could use your help. Don’s been killing himself trying to figure it out.”

“Sure, of course. Just give me a second to finish up here, and you can tell me about it.” Charlie turns back to his groupies, smiling, chalk at hand. Colby grins.

The second’s more like ten minutes, but eventually the last of the girls leaves and Charlie turns to Colby. “And what was your question?” he asks, grinning.

“Oh, yeah,” says Colby. “Sorry, Professor, I just couldn’t get number twenty-seven _b_ , I tried for _hours_.” Too weird, going straight back to college again, and he shakes his head. “Actually, I’ve never taken much math, just basic algebra and stats. Couldn’t even tell you what calculus is, really.”

“Oh, we’ll have to rectify that someday,” says Charlie, eyes going wide. “It’s really very simple—both the concept and the basic derivative and integral formulas, I could explain the foundations in just a few minutes—”

He loves this guy. “Maybe after we talk about the case.”

“Right, right, the case. Let me get my stuff—” he turns to the table and podium. Colby gets to the books first. They’re as heavy as they look.

“Oh, you don’t have to—”

“I got ’em, no problem. You’ll have to lead the way, though. I got totally turned around looking for this place; I have no idea where your office is.”

“Oh, well—” Charlie holds the door for him, “—follow me.”

 

“Oh, bank fraud. Like—whatever his name was.” Charlie starts in on pyramid schemes and stealing two cents at a time. Colby’s already heard a secondhand version of this from Don, but it’s cool listening again, because he always _gets_ stuff when Charlie explains it.

“You know,” he says during a pause, “if I’d had you as a professor back in college, I might have done more than just the required math courses. You actually make this stuff kind of interesting.”

Charlie pauses just outside his office, and turns, blinking. “Wow, um—thanks. Thanks a lot.” He smiles, quick and a little awkward. “That really means a lot to me. That’s one of the things that makes teaching worthwhile, you know, inspiring people to do things they might not have done before—you know, I teach a class, math for non-mathematicians, you should come sit in one of these days. My dad likes to go, when he has time, he says he enjoys it—”

“Hey, that sounds really interesting,” says Colby, and normally that’d just be a line, but he thinks that maybe he’ll actually go sometime. Come to the university, hang out and listen to Charlie talk about math when he isn’t under pressure to make that math _mean_ something, maybe hang around and steal some more gumballs from Charlie’s office after, fun times had by all. Sure.

He wonders if Don will get mad if he socializes with his kid brother.

—actually, the picture that springs immediately to mind is Don telling him to make sure Charlie has a good time, bring him home by ten, and don’t hurt him on pain of slow torture. Colby has to snicker at that, which fortunately slips past Charlie unnoticed, because…well. It’s funny because it’s _true_.

This time, he gets the door, and Charlie ducks through and establishes himself in the—Charlie-ness—that is his office. Colby watches him and thinks, well…Charlie is kind of…

And that’s a _no_. Colby learned long ago that if you can go for the girls, you go for the girls, and forget about anything else, and he’s been squashing guy-noticing ever since, making everyday life easier. And shit, forget everyday life, try being a gay FBI agent. Not something Colby Granger wants to do, ever, no way. And he’s _not_ a pansy, and he doesn’t want to have to spend all his time proving that, and he decided this a while ago, so he doesn’t need to argue with himself about it because of his boss’s cute geeky younger brother.

And put that way, it sounds more than ridiculous enough to drop right there. He turns to Charlie, who’s putting stuff away, and offers the books. “Mind if I take another gumball?”

“Go ahead—just a second, let me put these over here—okay, which one?”

“This yellow one.” He holds it up, waits for Charlie to turn around and see it before popping in his mouth. Is there something special about each specific gumball, he wonders, or is it the color, or the place he takes it from, or what?

“Great, let me write this down…okay. Now, the case. You want to find out who’s been accessing the bank’s system and stealing the money.”

He chews. “Right.”

“Well, I’m assuming you’ve looked for a way to trace the user back from the transaction…” and Charlie’s off and running. He talks his way through a couple of algorithms that Colby’s never heard of, and really, he’s even fun to listen to when Colby has no idea what he’s talking about. He’s just so fucking _smart_ , and watching a brain move that fast is crazy but cool.

And…okay. He probably should have noticed this before, but he thinks the math thing slipped it under his radar. Maybe…he shouldn’t go to the math-for-dummies lecture.

But dammit, he wants to. And it’s not like he can’t sublimate attraction. 

“…so I might be able to work something out, if I talk to Klisky in Computer Science. I’ll call the office tomorrow and tell what I’ve got, sound good?”

“Sure.” He smiles around the gum. “So how about that intro to calculus?” Mistake, mistake, mistake, you _idiot_ , yells his brain, but flirt-mode is _on_ and he can’t turn it off.

“Oh—of course. Here, let me just—” Charlie pulls a blackboard over. “You really want to learn some calculus?”

“I—really, really do.” Solemn, laughing, but it’s the truth. Mysteries of the universe revealed, and who the hell is doing it for him? None other than the famous Dr. Charles Eppes.

“Okay,” says Charlie, “so, first I’m going to give you a quick conceptual explanation, show you why calculus is a useful form of math, what it does in the real world.”

“Math does stuff in the real world?” Colby widens his eyes. “I didn’t know that.”

“Okay, that gets you extra homework tonight. Now listen. Basic calculus does essentially two things, derivatives and integrals. A derivative measures a changing slope. Imagine a car on the highway.”

“Okay.”

“Now, this car doesn’t have cruise control, so it’s not going at a constant velocity.” Charlie grins. Colby loves these little metaphor things, if only because Charlie can find them _anywhere_. “Let’s say it’s accelerating. Now, if we want to graph the distance it’s gone, it’ll look like this,” and he turns and starts drawing on the board, talking about distance and velocity and acceleration and stuff Colby vaguely remembers not caring about in high-school physics. But—he puts it in order, carefully, and it’s really not hard to understand at all. “It’s just measuring something that changes,” says Charlie, tracing the curve with a finger. “The slope is _different_ at all these points, which means you need an equation to find it. You put the _x_ and _y_ points into the equation, and you have the slope.”

And—it’s like magic. He _gets_ it. He’s always been vaguely jealous of people who really got math and physics and all that rocket-science stuff, of his buddies in college who talked about theorems and hypotheses and wrote crazy symbols all through their notebooks. _Calculus_ was this impossibly hard concept; he’d look at his sophomore year roommate’s homework every now and then, and shudder. Greek letters and equations that went on for pages, like the stuff Charlie writes on the board when he’s _not_ teaching dumb-ass FBI agents what calculus is.

But the point is, this is _easy_. He really hadn’t thought he’d understand it, that he’d just be listening to Charlie talk as though it were some big insane case-theorem. He’s suddenly kind of pissed at himself and at his buddies, for making it seem like something totally impossible, some weird higher plane of understanding. It’s—easy.

And it’s even easier when Charlie gets to the actual math part of it, which is unbelievable. “A basic derivative is very simple,” he says, serious. “If all you’re working with is an equation with _x_ variables, what you do is multiply the variable’s power by its coefficient, and then subtract one from the power.”

Those are some words that Colby never learned or doesn’t remember, but then Charlie demonstrates, and _x 2_ becomes _2x_ , and it really _is_ easy.

“Weird,” he says, staring.

“You’re understanding it?” Charlie asks, watching him. “Do you want me to show you some more?”

“I get it. I really get it. But—yeah, show me some more.” He’s grinning. He gets calculus. This is insane.

Charlie goes through a few more equations, then writes another one and hands him the chalk. “You do this one.”

“What, me?” He looks at it, kind of half-laughing. Okay, he can do this. _4x 5_ becomes _20x 4_, and right on down the line. He screws one up, basic multiplication mistake, but Charlie just says, “Ah—look at that one again,” in a sort of a _you know better than that_ voice, and he just fixes it and moves on. It’s still easy.

“I don’t get it,” he says, once he’s finished it off with the constant becoming zero—and seriously, he never knew that stuff to the power of zero was one. He’s going to have to get Charlie to explain that, later, if it’s not some insanely complex thing that only mathematicians understand—“Everyone thinks of calculus as this big impossible higher math thing. I mean, if a math idiot like me can do it, why can’t every joe on the street?”

“I believe everyone _can_ ,” says Charlie, and of course he does, he’s a genius and a professor at one of the best math/science colleges in the country. But he goes on, “There’s a movie out there—I forget what it’s called, but it’s a true story about a teacher in some inner-city school who taught a group of kids calculus, and had them take the AP test. They passed, all of them. Anyone who wants to learn it, and has a competent teacher, is going to. Of course,” he grins, “the other side of the equation is that calculus does get harder as you go along. But all it really takes is attention and effort.” He turns to the board. “And before you know it, you’re doing stuff like this,” and there’s a Greek symbol or two, and little numbers above it and below it, and an infinity sign, and two or three different variables. Colby blinks.

“I have to say, I think that’s a little beyond me.”

“Well, right now, yes it is. But I could keep teaching you, and you’d be doing this pretty soon.” Big warm smile. “No problem. In fact…” and now he looks thoughtful, almost uncertain, “would you like me to?”

Uh. “Would I like you to what?” If this is what he thinks it is, he’s going to say no. Because it would be a bad idea.

“Keep teaching you. I’d really like to, if you want to learn. All we’d have to do is meet for half an hour here and there.” Now Charlie’s leaning forward on his toes, excited, looking up at Colby from under his eyelashes.

Bad. Idea. “Uh, yeah. That—I’d really like that.” He’s such an idiot. But he really, seriously, thinks that this is cool—he can learn _calculus_. Just like that.

“All right, great. Are you free—huh, let me see—Saturday afternoon?”

Jesus, Charlie’s going to take time out of his weekend for this? “You don’t have to—”

“Yeah, I do.” Another big smile. “I love teaching. I do it for free all the time, in addition to it actually being my job. I’m really, honestly, excited to do this. If you feel like you’re imposing, you can buy me coffee or something in return.”

And…“Okay,” he says. “There’s a Starbucks right near here…”

“Over on Hoover? All right, let’s meet there. Say, two o’clock?”

“Two’s fine for me.”

And suddenly Colby has…a math date. Or a private tutoring session from a professor that most people pay—whatever CalSci’s tuition is—to learn from, for the price of a cup of coffee. This is…crazy.

They do the small-talk goodbye stuff, and then Colby has a thought, and pauses on the way out. “Hey, Charlie?”

“Hm?” Charlie’s already staring at a board full of—something. Colby hopes he’ll actually hear him.

“Do you think you could keep this quiet, for now? Don’t tell your brother or anyone at the office?”

Charlie takes a break from the blackboard for a second. “Don’t want everyone knowing you’re a math geek?”

Colby isn’t sure if Charlie’s laughing or hurt. He…thinks laughing. Charlie has to have heard this every day of his life, anyway. He tries a grin. “Maybe I want to surprise them all later with my mad math skills.”

“Oh, I see.” Definite grin now, good. “All right. I’ll keep it under the table. See you on Saturday?”

“See you then.”

As Colby starts the search for his car, he thinks that yeah, this is probably a mistake. Sure, he can sublimate, but Charlie—has something. Something different, something more than just being a genius. Something that he’s betting is going to nuke his sublimation all to hell.

But he’s happier right now than he’s been since he moved to Los Angeles, so he doesn’t care.  


end  



End file.
